/**
 Do not return anything, modify s in-place instead.
 */
function reverseString(s: string[]): void {
    let low = 0;
    let high = s.length - 1;
    while (low < high) {
        const temp = s[low];
        s[low] = s[high];
        s[high] = temp;
        low++;
        high--;
    }
};

const str = ["h", "e", "l", "l", "o"];
reverseString(str);
console.log(str);